Design of Integrated Water System

Abstract

The thesis is composed of two parts. In the first part, novel automated design method for the water networks has been developed to consider impacts of pressure drop and pumping arrangement in the network design. A superstructure-based optimisation framework has been developed to systematically consider all the key design issues simultaneously, including flowrate constraints, pressure-drop constraints and other operational constraints, as well as to fully accommodate rigorous economic trade-off between fresh water cost, piping cost, and pumping cost. The proposed optimisation study enables the identification of the optimal distribution of water within the network, together with most appropriate location and capacity of pump required for water systems, which provides a cost-effective and realistic configuration of water networks. The network complexity has been readily controlled by imposing design constraints in the optimisation. In the second part, an automated design method for the water networks under uncertain process conditions has been developed. To deal with the uncertainty problem, the installation of buffer tank and the installation of supplementing pipelines are systematically considered in the design of water networks. The cost-effective and feasible distribution and reuse of water within the network is identified from the superstructure-based optimisation model, with which all the operational constraints and fluctuating operating characteristics for water-using operations are fully and simultaneously reflected. The optimisation framework provides rigorous economic evaluation of the network through trade-off between operating and capital costs under uncertainty. The conceptual insight related to the design of water networks is incorporated in developing a reliable solution strategy which can effectively deal with the difficulty in solving the mixed-integer nonlinear programming problem in both parts. Case studies are given to validate the proposed models and demonstrate the importance of considering pressure drop constraints in practice and the uncertain process conditions in the design and optimisation of water networks.

Date of Award	31 Jul 2012
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Robin Smith (Supervisor)